A wireless base station device of a wireless communication system may create a signal frame of wireless information on the basis of an IP packet received from an Internet protocol (IP) network. An IP packet includes data to be forwarded to a mobile station and element information for specification of a destination, and a wireless base station device forwards a signal frame including data to the mobile station according to the element information. The element information is, for example, header information included in the IP packet, and includes information such as an IP address, a port number, a protocol identifier, a communication identifier, etc.
In this case, the wireless base station device holds management information for association between the element information and the destination mobile station, and forwards data to a mobile station corresponding to the element information included in the received IP packet. However, since there is a large amount of element information, such as an IP address, etc., the amount of management information becomes enormously large if the number of mobile stations accommodated by the wireless base station device increases.
Then, the wireless base station device provides a forwarding table in which a destination is registered using a hash value of element information as an index, and determines in many cases a destination on the basis of the hash value of the received element information. Using a hash value, the increase of the management information registered in the forwarding table may be suppressed.
There is also a known method of generating a data identifier for identification of data to be forwarded among a plurality of processors (for example, refer to patent document 1). In this method, a data group is extracted in which a processor which uses certain data is different from a processor which generates the data according to the information about the range of the data used by each processor and the information about the range of the data generated by each processor. Then, a data identifier is allocated only to the data of the data group.
Also known is an identification information forwarding system which forwards the identification information of a plurality of packet routes which may be set for each link between nodes adjacent in a packet communication network from a first communication unit to a second communication unit (for example, refer to the patent document 2).
Also known is a duplicate Web site detection device which generates site information by retrieving a content hash value, a site name, and an intra-site path corresponding to each site from Web page information, and detects a duplicate site group according to the site information (for example, refer to the patent document 3).    Patent Document 1: Japanese Laid-open Patent Publication No. 4-205543    Patent Document 2: International Publication Pamphlet No. WO 92/22972    Patent Document 3: Japanese Laid-open Patent Publication No. 2006-215735